As chemical warfare agents pose an ever increasing risk, an urgent need exists for reliable sensors. Ideally, a sensor would be portable and operate in ambient conditions to reliably detect a wide variety of chemical warfare agents (CWA) with exceptional sensitivity, selectivity and response time. In addition, the resulting system must be rugged, cost effective and of simple design, such that it may readily be deployed in any environmental setting. Particularly problematic for conventional sensors are the requirements for response time and sensitivity in ambient conditions.
Among the many chemical warfare agent of special interest to counterterrorism and military personnel are nerve, blister and pulmonary agents. Nerve agents include organophosphorous compounds, such as 1-Methylethyl methylphosphonofluoridate (sarin, GB); 1,2,2-Trimethylpropyl methylphosphonofluoridate (soman, GD); Cyclohexyl methylphosphonofluoridate (GF), Ethyl dimethylphosphoramidocyanidate (tabun, GA), and O-Ethyl S-(2-isopropylaminoethyl) methylphosphonothiolate (VX). Blister agents include organosulfur compounds, such as distilled bis(2-chloroethyl) sulfide (mustard, HD). Pulmonary agents include acid chlorides, such as phosgene (CG) and blood agents such as cyanogen chloride (CK).
A number of techniques for CWA detection have been investigated. These include gas chromatography (GC), liquid chromatography (LC), mass spectrometry, nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. Sensors based on thermoelectric effect, fiber optic/surface plasmon, solid state electrochemical, MOS devices, surface acoustic wave, and others have been devised. While such technologies may be effective for CWA detection, none have the desired aggregate characteristics, as described above.
What is needed is a cost-effective, rugged, easy to use, portable sensor system that operates in ambient conditions and without need of an external or integrated heater and also reliably detects a wide variety of chemical warfare agents (CWA) with exceptional sensitivity, selectivity and response time. The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above.